Healthy Living

The Difference Between Crohn's Disease and Ulcerative Colitis

The Difference Between Crohn's Disease and Ulcerative Colitis

Crohn’s disease is a chronic inflammatory bowel disease that affects the lining of the digestive tract. Ulcerative colitis is also characterized as a chronic, inflammatory bowel disease that causes inflammation in the digestive tract. Hence, both Crohn’s disease and ulcerative colitis (UC) are classified under irritable bowel diseases (IBDs) because they both affect the digestive tract. Their symptoms are also quite similar for the same reason, but they are actually quite different in several ways:


Crohn’s disease can affect any part of the digestive tract from the mouth to the anus, but it is most common at the end of the small intestines, the region known as the ileum, and the beginning of the large intestine. The most common sites of intestinal involvement in Crohn’s disease are ileal, ileocolic and colonic. Ulcerative colitis, on the other hand is only limited to affecting the colon and does not reach or spread to any other parts of the digestive tract.

Besides the area affected another difference between Crohn’s disease and Ulcerative coloitis is that Crohn’s disease affects usually the whole thickness of the digestive tract, while ulcerative colitis only affects the top lining of the colon.

Whenever Crohn’s disease is detected through endoscopy, the area affected and inflamed is inconsistent, with some parts being spared. Ulcerative colitis, on the other hand, is signified by a continuous inflammation throughout the colon.


As mentioned earlier, most of the symptoms of both Crohn’s disease and Ulcerative colitis are very similar. Some of the symptoms common in both cases are:

  • An increased urgency to perform bowel movements
  • Abdominal pain, particularly in the lower back or in one side of the abdomen
  • Feeling as though you have not completely emptied your rectum after bowel movement
  • Fatigue, weakness, lethargy and a general loss of energy
  • Loose stools and diarrhoea
  • Blood in the stool, etc.

Because Crohn’s disease is extensive and affects an extensive part of the digestive tract, it usually manifests itself in severe symptoms that are unique. Some of these symptoms include:

  • Bleeding in the rectum and pains due to tearing in the lining of the anus
  • Development of a fistula, which is also due to ruptures in the digestive tract that is a connection between the intestines and the skin, bladder or vagina
  • Loss of weight is common in patients with Crohn’s disease because nutrients cannot be absorbed properly by their small intestines
  • Inflammation of the skin, eyes and joints
  • Inflammation of the liver or the bile ducts
  • Delayed growth or sexual development, in children



The exact causes of Crohn’s disease arestill unknown and not very well understood. Recent studies have suggested that heredity, genetic factors, or environmental factors contribute to the development of Crohn’s disease. Similar to Crohn’s disease, Ulcerative colitis’s causes are still unknown as well. Many researchers now believe that stress in not the cause of this condition. Researchers are now focusing on identifying causes that relate to the immune system or a person’s heredity.

The exact cause of both Crohn’s disease and UC is still unknown, despite being discovered back in the 1930s. In the past, factors such as diet and stress were attributed to the development of these IBDs, but research has not shown any direct link. Researchers are now concluding that both of these IBDs may be the result of an autoimmune disorder. In certain people, their immune system identifies certain food particles as pathogens and thus sends in white blood cells to prevent infection. In the process, the lining of the digestive tract becomes inflamed, and this eventually develops into ulcers.

Nevertheless, both these Irritable bowel syndromes have different contributing factors.

Risk/contributing factors for Crohn’s disease may include the following:

  • Young people are more likely to develop this condition. Many people who have been diagnosed are under the age of 30.
  • Though the disease can affect people from any ethnic groups, whites and people of eastern European origin have higher risk than others in developing this disease.
  • Having a close relative, such as a parent, sibling or a child, with the diseases poses a higher risk of you developing it yourself. As many as 1 in 5 people with Crohn's disease have a family member with the disease.
  • Cigarette smoking is one of the most controllable risk factors of Crohn’s disease. Smoking leads to increased complications and could hence necessitate surgery in some patients who have severe forms of the disease.
  • Nonsteroidal anti-inflammatory medicines have been known to increase the inflammation of the bowel which could worsen the Crohn’s disease. These medicines include ibuprofen, naproxen sodium, diclofenac sodium, and other medicines.
  • It has been found that where you live also affects your risk of developing the Crohn’s disease. If you live in an urban area or a heavily industrialized one, then you are more likely to develop this disease. This is suggestive of the fact that environmental factors such as high fat rich foods or refined foods also have a role to play in causing Crohn’s disease. People living in northern climates also seem to be at a greater risk than others.

Some of the risk factors for UC are similar to Crohn’s disease. Ulcerative colitis has the following risk/contributing factors:

  • Contrary to Crohn’s disease there isn’t a definitive age range at which ulcerative colitis develops. While it has been found to begin before the age of 30 it can equally likely occur at any age, and some people may not develop it until they are 60 years old.
  • Whites also have a higher risk of developing ulcerative colitis, similar to the Crohn’s disease. Having said that, it can also occur in any race.
  • If you have a family member affected by the disease, such as your parent, child or a sibling, then you are at a higher risk at developing this disease.
  • The use of Isotretinoin also poses a risk in developing UC, but a definitive link between the two has yet to be established.

Crohn’s disease and Ulcerative Colitis are issues that need to diagnosed immediately, and for this, medical guidance is immensely important.

Key Takeaways

  • Both Crohn’s disease and ulcerative colitis (UC) are classified under irritable bowel diseases (IBDs).
  • There is a difference in the location, severity and the symptoms of these diseases. 
  • Despite having discovered back in the 1930s, the exact cause of both Crohn’s disease and UC is still unknown.